package library

import (
	"io/fs"
	"os"
	"path/filepath"
	"testing"
	"time"

	"gitbay.org/cmc/gallery/internal/format"
)

func statFile(t *testing.T, body string) (string, fs.FileInfo) {
	t.Helper()
	p := filepath.Join(t.TempDir(), "a.jpg")
	if err := os.WriteFile(p, []byte(body), 0o644); err != nil {
		t.Fatal(err)
	}
	fi, err := os.Stat(p)
	if err != nil {
		t.Fatal(err)
	}
	return p, fi
}

func TestMetaCacheRoundTrip(t *testing.T) {
	path := filepath.Join(t.TempDir(), "sub", "meta.json")
	c, err := OpenMetaCache(path)
	if err != nil {
		t.Fatal(err)
	}
	_, fi := statFile(t, "x")
	m := format.Meta{Width: 3, Height: 2, Camera: "X-T5", Taken: time.Date(2025, 3, 1, 0, 0, 0, 0, time.UTC)}
	c.put("tokyo/a.jpg", fi, m)
	c.put("gone/b.jpg", fi, m)
	if err := c.save(map[string]bool{"tokyo/a.jpg": true}); err != nil {
		t.Fatal(err)
	}

	c2, err := OpenMetaCache(path)
	if err != nil {
		t.Fatal(err)
	}
	got, ok := c2.get("tokyo/a.jpg", fi)
	if !ok || !got.Taken.Equal(m.Taken) || got.Camera != "X-T5" || got.Width != 3 {
		t.Fatalf("get = %+v, %v", got, ok)
	}
	if _, ok := c2.get("gone/b.jpg", fi); ok {
		t.Fatal("entry outside keep survived save")
	}
}

func TestMetaCacheMissOnChange(t *testing.T) {
	c, _ := OpenMetaCache(filepath.Join(t.TempDir(), "meta.json"))
	p, fi := statFile(t, "x")
	c.put("a.jpg", fi, format.Meta{Width: 1, Height: 1})

	if err := os.WriteFile(p, []byte("longer"), 0o644); err != nil {
		t.Fatal(err)
	}
	fi2, _ := os.Stat(p)
	if _, ok := c.get("a.jpg", fi2); ok {
		t.Fatal("size change should miss")
	}

	later := fi.ModTime().Add(time.Hour)
	os.WriteFile(p, []byte("x"), 0o644)
	os.Chtimes(p, later, later)
	fi3, _ := os.Stat(p)
	if _, ok := c.get("a.jpg", fi3); ok {
		t.Fatal("mtime change should miss")
	}
}

func TestMetaCacheCorruptStartsEmpty(t *testing.T) {
	path := filepath.Join(t.TempDir(), "meta.json")
	os.WriteFile(path, []byte("{nope"), 0o644)
	c, err := OpenMetaCache(path)
	if err != nil {
		t.Fatal(err)
	}
	if len(c.entries) != 0 {
		t.Fatalf("entries = %v", c.entries)
	}
}